Variable not set(synchronization

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FATAL ERROR in
action number 1
of Create Event
for object janbulletmp:

Variable janbulletmp.i(100005, -2147483648) not set before reading it.
at gml_Object_janbulletmp_CreateEvent_1 (line 2) - gms_instance_sync(i, is_extended, "canshoot")
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create event in janbulletmp
gms_instance_sync_var_add("canshoot",canshoot);
gms_instance_sync(i, is_extended, "canshoot")


i have tried thosuands of combinations but when i press space(shooting key) the game crashes. I googled everywhere and looked at forums but couldnt get an answer